The present invention relates to test kits and methods for detecting the presence of a pathogen in a test sample. The test sample may be obtained from a patient or alternatively from a source of food or drink that may contain pathogens.
Diseases such as encephalitis, cephalomeningitis, meningitis, pneumonia, enterogastritis, endocarditis, urinary infectiosus, are caused by infection by a pathogen. The pathogens include different bacteria, viruses, fungi and protozoa. Different pathogenic infections commonly have similar symptoms resulting in difficulties in providing an accurate diagnosis of the cause of the infection or disease. For example, encephalitis and meningitis patients generally manifest fever, headache, and convulsion. Identifying the pathogens responsible for these symptoms quickly and accurately is important to determining which medication to prescribe. Current diagnostic procedures for identification of pathogens include microscopic examination, microbiological culturing, serum immunity test, and Polymerase Chain Reaction (PCR). These procedures require highly trained staff and are very time consuming.
According to the conventional PCR method, a test sample containing a gene functioning as a template is mixed with at least one pair of PCR primers designed so as to amplify at least one gene having a specific length. By subjecting the amplified PCR product to electrophoresis using agarose gel and staining it, the PCR product is visualized. According to the PCR method, the gene contained in the test sample is identified based on the length of the visualized PCR product. Multiple primer pairs can be amplified in the same sample in order to screen for multiple genes more efficiently.
However, as the number of PCR primers contained in a primer reagent is increased, “noise” on an electrophoresis gel is increased. “Noise” occurs when PCR products are produced due to non-specific annealing. For this reason, when a PCR reaction is used, it is difficult to determine the presence of more than only a few genes.
Additionally, it is necessary to design the primers so that the PCR products amplified by the PCR reaction are distinguishable on electrophoresis gels, which often have limited resolution. Designing PCR primers that produce suitably distinguishable PCR products with low noise is difficult and time consuming. Thus, a strictly PCR/electrophoresis-based approach is inefficient for screening for expression of a large number of genes.